clocksource: em_sti: Convert to devm_* managed helpers

Replace kzalloc, clk_get, ioremap and request_irq by their managed
counterparts to simplify error paths.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/clocksource/em_sti.c

@@ -315,68 +315,47 @@ static int em_sti_probe(struct platform_device *pdev)
 {
 	struct em_sti_priv *p;
 	struct resource *res;
-	int irq, ret;
+	int irq;
 
-	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
 	if (p == NULL) {
 		dev_err(&pdev->dev, "failed to allocate driver data\n");
-		ret = -ENOMEM;
-		goto err0;
+		return -ENOMEM;
 	}
 
 	p->pdev = pdev;
 	platform_set_drvdata(pdev, p);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		dev_err(&pdev->dev, "failed to get I/O memory\n");
-		ret = -EINVAL;
-		goto err0;
-	}
-
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
 		dev_err(&pdev->dev, "failed to get irq\n");
-		ret = -EINVAL;
-		goto err0;
+		return -EINVAL;
 	}
 
 	/* map memory, let base point to the STI instance */
-	p->base = ioremap_nocache(res->start, resource_size(res));
-	if (p->base == NULL) {
-		dev_err(&pdev->dev, "failed to remap I/O memory\n");
-		ret = -ENXIO;
-		goto err0;
-	}
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	p->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(p->base))
+		return PTR_ERR(p->base);
 
 	/* get hold of clock */
-	p->clk = clk_get(&pdev->dev, "sclk");
+	p->clk = devm_clk_get(&pdev->dev, "sclk");
 	if (IS_ERR(p->clk)) {
 		dev_err(&pdev->dev, "cannot get clock\n");
-		ret = PTR_ERR(p->clk);
-		goto err1;
+		return PTR_ERR(p->clk);
 	}
 
-	if (request_irq(irq, em_sti_interrupt,
-			IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
-			dev_name(&pdev->dev), p)) {
+	if (devm_request_irq(&pdev->dev, irq, em_sti_interrupt,
+			     IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
+			     dev_name(&pdev->dev), p)) {
 		dev_err(&pdev->dev, "failed to request low IRQ\n");
-		ret = -ENOENT;
-		goto err2;
+		return -ENOENT;
 	}
 
 	raw_spin_lock_init(&p->lock);
 	em_sti_register_clockevent(p);
 	em_sti_register_clocksource(p);
 	return 0;
-
-err2:
-	clk_put(p->clk);
-err1:
-	iounmap(p->base);
-err0:
-	kfree(p);
-	return ret;
 }
 
 static int em_sti_remove(struct platform_device *pdev)